Abstract: The in vitro antibacterial activities of amikacin made in China were tested against 480 strains of commonly encountered bacterial pathogens, including S. aureus, E. coli, P. aeruginosa, Klebsiella, Enterobactor, Proteus, etc, by double dilution method, and were compared with the activities of kanamycin, gentamicin, tobramycin, streptomycin, and Japan made amikacin.The results indicated that amikacin has a broad spectrum of antibacterial activities against common bacterial pathogens, and agreed fairly well with the activities of Japanese product. Amikacin is apparently much superior in activity when compared withgentamicin, tobramycin, and kanamycin. The real value of this new aminoglycoside antibiotic is that amikacin is usually active against bacteria that is resistant to other aminoglycosid antibiotics.